B-Series (Compact)

B21, B2100, B2400, B2410, B26, B2630, B2710, B2910, B3030, B3200, B3300, B7500, B7510, B7610, B7800, B8200, B9200.

L-Series (Standard Utility)

L2500, L2600, L2800, L2900, L3000, L3010, L3130, L3200, L3240, L3300, L3400, L3410, L3430, L35, L3540, L3600, L3710, L3800, L3830, L39, L3940, L4200, L4240, L4300, L4310, L4330, L4400, L4600, L4610, L4630, L4740, L48, L5030, L5240, L5740.

M-Series (Utility)

M4700, M4800, M4900, M5400, M5700, M59, M6800, M7040, M8200, M8540, M9000, M9540.

MX-Series

MX4700, MX4800, MX5000, MX5100, MX5200, MX5800.

05 Series

D905, D1005, D1105, V1205, V1305, V1505.

03 Series

D1403, D1703, V1903, V2003, V2203, V2403 (This matches the other parts you’ve been asking about).

Super Mini Series

Z482, D722.

Older Series

L2000, L2201, L2250, L2550 (L-Series engines).

• Inner Diameter (ID) : 7.0 mm (Standard for Kubota 7mm valve stems)
• Outer Diameter (OD) : 10.0 mm
• Total Height : 6.5 mm
• Material : Case-Hardened Alloy Steel
• Surface Finish : Polished / Ground (to minimize friction)
• Hardness : Typically HRC 55-60 (Rockwell Scale)

15221-13282 Current Successor: The most modern revision, often featuring improved heat treatment.

15221-13283 Alternative Revision: Sometimes found in newer “03-M” or “05” series parts manuals.

70000-65201 Legacy Accessory Code: Occasionally used in older North American wholesale catalogs.

A-15221-13280 Aftermarket Code: Standard identifier for brands like Reliance, Maxiforce, or Vapormatic.